Attacking/casting 50% slower

There are various skills which say "make target attack 50% slower" or "cast 50% slower".

Now, do they mean this literally; i.e. a warrior might attack once every 3 secs instead of every 2 secs, and the casting time of spells is 1.5x.

Or do they really mean "attack rate is cut in half" in which case a warrior might attack once every 4 secs instead of every 2 secs, and the casting time of spells is doubled.

Good question. But from my observation, it is actually attackrate cut in half + casting time doubled.

There is no skill that makes someone cast 50% slower. It says 2x longer or attack slower then normal. But attacking slower then normal, I'm not sure if they mean 1/2 as fast.